Steam continuous stripper idea

[tommysb]

He's running 6kw, and about 3 l/pm, in other videos it shows him making the mash. He does a wheat flour vodka.

That's about 180l per hour, maybe 3x the rate we might expect if we take the 400w/g/h! Sorry to derail the thread - I was searching for more info because his setup looks great and you seemed to have some more insights. I found his other youtube channel which has other videos and more info:
https://www.youtube.com/@alexandertsets ... 375/videos

He seems to run a bigger one with 22-24kW for stripping - that seems more correct if he's doing 180l per hour maybe? and 5-6kw in his reboiler for boiling the low wines? Anyway sorry for going off topic!

[Bolverk]

He's running 6kw, and about 3 l/pm, in other videos it shows him making the mash. He does a wheat flour vodka.

That's about 180l per hour, maybe 3x the rate we might expect if we take the 400w/g/h! Sorry to derail the thread - I was searching for more info because his setup looks great and you seemed to have some more insights. I found his other youtube channel which has other videos and more info:
https://www.youtube.com/@alexandertsets ... 375/videos

He seems to run a bigger one with 22-24kW for stripping - that seems more correct if he's doing 180l per hour maybe? and 5-6kw in his reboiler for boiling the low wines? Anyway sorry for going off topic!

His got a bigger column now but this old 4"one in the video he's is running a crazy high efficiently rate. 408 was the average Larry found, but Alex was get something like 250 w pg/ph... but he's got so much hx going on... 4 PCs and runs his beer through a coil that's in his effluent, and runs is water for his steam through the effluent to preheat it as well.

[Bolverk]

That makes sense

So you know the math better than I, at what power input would you reach the point where you would condense all the vapor with the setup as drawn? Would decreasing the input power from say 1650w to 1400w give you complete condensation?

[pipes+hose]

That makes sense

So you know the math better than I, at what power input would you reach the point where you would condense all the vapor with the setup as drawn? Would decreasing the input power from say 1650w to 1400w give you complete condensation?

The first problem with calculating that is that there's other variables (like thermal loss in various parts, others i can't think of our don't know about) that will throw it off.

The second problem is it's only a starting point, you'll have to play with things to see how they work.

<edit: the following isn't true, i made an error in my calculation.>
The third problem is that i think for 50% output low wines you'll never find a balance point where product condensing power is equal to beer warming power, there will always be more need for condensing. Unless your beer feed to be really low abv, but that's sort of like just putting cooling water into the beer to be separated and sent down the drain. That sounds not so bad relative to a new pc that's feed water that will go down the drain but using a really low abv beer means you need better seperation to get that 50% out.

I think your best to get a simple aux pc.

[Bolverk]

That makes sense

So you know the math better than I, at what power input would you reach the point where you would condense all the vapor with the setup as drawn? Would decreasing the input power from say 1650w to 1400w give you complete condensation?

The first problem with calculating that is that there's other variables (like thermal loss in various parts, others i can't think of our don't know about) that will throw it off.

The second problem is it's only a starting point, you'll have to play with things to see how they work.

The third problem is that i think for 50% output low wines you'll never find a balance point where product condensing power is equal to beer warming power, there will always be more need for condensing. Unless your beer feed to be really low abv, but that's sort of like just putting cooling water into the beer to be separated and sent down the drain. That sounds not so bad relative to a new pc that's feed water that will go down the drain but using a really low abv beer means you need better seperation to get that 50% out.

I think your best to get a simple aux pc.

Makes sense

Ok so simple aux pc, hell it is only there as a safety and is only going to be knocking down 500w worth of heat you could probably safely do it out of a bucket of cold water and change the bucket water occasionally

[zach]

For example warming 10L of 10%abv beer from 20 to 92C (92 is the boiling temp of 10% abv) takes about 815 watt hours. Condensing the 2L of 50% low wines (that you get out of 10L of beer) means removing around 1350watt hours of heat. So you have 1350 wh of low wines heat to remove, 815 can go to your beer but there's still 535wh of heat/vapor left to condense.

I agree with your number for the sensible heating with the 10 Liter of 8% from 20 to 92 C. I don't agree with your condenser numbers.

What did you have for the latent heat of vaporization for the 50% abv condensate? I arrived at 1,640 J/g based on 44% mass fraction ethanol using the values on this page: https://homedistiller.org/wiki/htm/calcs/calcs_calc.htm

With the 815 watts hours of cooling capacity from the beer, it is possible to generate 2 liters of 50% abv condensate in the heat exchanger.

Condensate Mass = 815 Watt hr x 3600 J /Watt hr x 1 / 1640 J/g = 1,789 grams

Condensate Volume = 1,789 grams / .89 gram/ml = 1,998 ml

With 10 liter/hr of feed at 8% abv it looks like the mass and energy balance works out with about 1.7 kw heat input and no heat losses to atmosphere.

It would be possible with a positive displacement pump to drive up the liquid pressure in the heat exchanger to elevate the boiling point of the beer. At 2.5 bar pressure the boiling point is 112 C for a 10% abv. A metering valve or orifice would be required at the liquid outlet to prevent flashing in the heat exchanger prior to injection in the column. I don't think its necessary from an energy balance stand point, but might make operation more stable.

[pipes+hose]

For example warming 10L of 10%abv beer from 20 to 92C (92 is the boiling temp of 10% abv) takes about 815 watt hours. Condensing the 2L of 50% low wines (that you get out of 10L of beer) means removing around 1350watt hours of heat. So you have 1350 wh of low wines heat to remove, 815 can go to your beer but there's still 535wh of heat/vapor left to condense.

I agree with your number for the sensible heating with the 10 Liter of 8% from 20 to 92 C. I don't agree with your condenser numbers.

What did you have for the latent heat of vaporization for the 50% abv condensate? I arrived at 1,640 J/g based on 44% mass fraction ethanol using the values on this page: https://homedistiller.org/wiki/htm/calcs/calcs_calc.htm

properties.jpg

With the 815 watts hours of cooling capacity from the beer, it is possible to generate 2 liters of 50% abv condensate in the heat exchanger.

Condensate Mass = 815 Watt hr x 3600 J /Watt hr x 1 / 1640 J/g = 1,789 grams

Condensate Volume = 1,789 grams / .89 gram/ml = 1,998 ml

With 10 liter/hr of feed at 8% abv it looks like the mass and energy balance works out with about 1.7 kw heat input and no heat losses to atmosphere.

It would be possible with a positive displacement pump to drive up the liquid pressure . **Truncated**

My condenser numbers: i didn't have access to my good spreadsheet so i was winging it from work on a basic/new excel sheet. I can't confirm right now due to the late hour and drinks, I will later. I also don't have access to my work spreadsheet that had the numbers i posted.

You're asking good questions, it's always good to understand what the numbers come from, and if the person giving those numbers (me) is correct. Engineering toolbox gives multiple latent heat of vaporization for ethanol. My home sheet uses 910 kj/kg (and 2256 for water). So at 44 (abw) mass fraction i get 1663. That's basically the same as you've posted. I'll check my sheet i did at work tomorrow for the test. I'll be able to follow your question/clarification better then.

[Steve Broady]

Based on the numbers I’m seeing here, would it be fair to say that there is some balance point at which a given ABV input can sustainably condense a given output without the need for supplemental cooling? Rough estimate would be 6% ABV input for 50% ABV output. And taking that a step further, it seems that they would have an inverse but roughly linear relationship. Or have I completely missed something obvious?

[pipes+hose]

Based on the numbers I’m seeing here, would it be fair to say that there is some balance point at which a given ABV input can sustainably condense a given output without the need for supplemental cooling? Rough estimate would be 6% ABV input for 50% ABV output. And taking that a step further, it seems that they would have an inverse but roughly linear relationship. Or have I completely missed something obvious?

I imagine such a point theoretically exists but that to actually make a still that ran on that point would be difficult. I would think difficult to the point that it couldn't be done without some safety margin. Kinda like making a bridge to drive a bicycle across; an inch wide might technically work but be functionally unusable, a foot wide could be used but there's still risk of getting off track, 5 feet wide is much more forgiving and nicer to use but costs more materials and effort.

[Steve Broady]

Based on the numbers I’m seeing here, would it be fair to say that there is some balance point at which a given ABV input can sustainably condense a given output without the need for supplemental cooling?
…

I imagine such a point theoretically exists but that to actually make a still that ran on that point would be difficult. I would think difficult to the point that it couldn't be done without some safety margin.

I agree that actually running at that balancing point would be tricky. Rather, I was thinking that these things obviously do work, because some people have done it. But it may be that they’re pretty close to the limit beyond which supplemental cooling is needed. 6% beer input is not that crazy a number, and 50% or more output also not crazy. But that could also be why some people have had a lot of trouble getting the idea to work. It’s really close to the edge, which makes it very sensitive.

It seems to me that doing the math and knowing how much of a margin we have would be helpful in both design and troubleshooting.

It also sounds like, on a hobby scale, the supplemental cooling needed might be relatively minimal, and well within the practical range of air cooling.

[pipes+hose]

For example warming 10L of 10%abv beer from 20 to 92C (92 is the boiling temp of 10% abv) takes about 815 watt hours. Condensing the 2L of 50% low wines (that you get out of 10L of beer) means removing around 1350watt hours of heat. So you have 1350 wh of low wines heat to remove, 815 can go to your beer but there's still 535wh of heat/vapor left to condense.

I significantly screwed up a calculation. I took the mass of eth and multiplied it by the latent heat of vaporization and reported it as wh , i forgot to factor in 3600 for hr and 1000 for kilo j to make it correctly wh.

Redoing the calculation isn't looking reasonable here at work. I'm going to have to look again at my home sheet and run it there.

I need to edit my previous posts to show the inaccuracy and future readers, and to clarify what this means in terms of still function and preheating.

Thanks for bringing this up zach!

[tommysb]

I agree that actually running at that balancing point would be tricky. Rather, I was thinking that these things obviously do work, because some people have done it. But it may be that they’re pretty close to the limit beyond which supplemental cooling is needed. 6% beer input is not that crazy a number, and 50% or more output also not crazy. But that could also be why some people have had a lot of trouble getting the idea to work. It’s really close to the edge, which makes it very sensitive.

I think these things get finnicky on a small scale - but things like Coffey stills have been doing some sort of variation of this idea for hundereds of years with probably less 'clever' control systems than we have these days.

NormandieStill recently shared a mobile continuous still that was used on the road in France and IIRC the vapours were condensed by just the incoming cider....

[tommysb]

Also I think the 50% output is just a figure from the VLE curves - e.g. for a fixed input abv, a single stage of distillation is what defines the output abv. The idea of the stripping column is not to do any further enrichment or increase in ABV, that would be for a rectification section that comes after/above the wash feed point.

I understood that Bolverk's target of 50% was based on this - that his input wash would be about 8%. If he used a lower abv wash, then the output abv would be less, but that's fine.

[jonnys_spirit]

I would personally prefer an output in the 30%abv range that can be proofed down further to the 25%abv range for a spirit run (bourbon/whiskey, not vodka/neutral)....

Other folks may and probably do have different goals so a design -requirement with an appropriately wide target output range would be quite peachy

Using more cooling water to reach a specific goal is acceptable in my mind but is still a resource that is not unlimited for all users...

Cheers,
jonny

[zach]

It seems to me that doing the math and knowing how much of a margin we have would be helpful in both design and troubleshooting.

It also sounds like, on a hobby scale, the supplemental cooling needed might be relatively minimal, and well within the practical range of air cooling.

I did several iterations of the calculation with different abv feed % and 20 C inlet to the beer preheater. (see below) In all cases there is enough cooling capacity with the beer feed to match the amount of condensate generated.

With 6% abv feed the beer outlet temp is 60 C prior to entering the column. Additional heat recovery from the still bottoms to further heat the feed would be good idea.

At 10% abv feed the beer outlet temp is 87.5 C. Additional heat recovery might not be necessary .

Thanks for bringing this up zach!

No problem. I rarely do calculations using SI units, so I wasn't sure until I double checked all my conversion factors.

I found calculator on the HD calculator page for Heat of Vaporization and adjusted my calculations in the above.

[Bolverk]

I would personally prefer an output in the 30%abv range that can be proofed down further to the 25%abv range for a spirit run (bourbon/whiskey, not vodka/neutral)....

Id just hold back a gallon or so of the clear beer to make sure I had enough to dilute down my low wine for the pot still run

[jonnys_spirit]

That's an option but I personally want all of the deep tails captured in the LW's so I can recycle feints into further spirit runs along with top-up-beer after the final cut like you might strip>spirit in a typical strip run (down to 25-30%abv aggregate). Maybe a continuous stripper isn't the solution for this approach?

Cheers,
jonny

[Bolverk]

Maybe a continuous stripper isn't the solution for this approach?

Cheers,
jonny

Hard to say man, columns can be detuned and run real funky or real clean.

Stoll and wolf is just as flavorable as any pot stilled whiskey as I've ever had, but you guys also know what the commercial stuff tastes like too. I really think its up to how the operator chooses to run it. A column stripped/pot cut may just be that perfect balance of finesse and funk.

[tjsc5f]

A column stripped/pot cut may just be that perfect balance of finesse and funk.

I watched a YouTubes video from Frey Ranch, they column strip and Spirit run in a pot. A lot of people like their stuff. I've only got my hands on one single barrel from there because it's not distributed in my state, but it definitely has some of that pot still funk.

It's my understanding that Bowman in Virginia uses a similar process, but they're getting their stripped product from Buffalo Trace and running it through their own pot still. I have a single barrel from here too, but it comes off as a much cleaner product.

[tommysb]

Hi Bolverk -

If the aim is simplicity, and that asks for a no-moving-part fixed capacity one-fill steam generator, you can also explore this really simple idea from Dr Gradus. (See around the 5 minute mark).



Essentially the column is over the boiler, which only boils water (e.g. a steam generator) and the wash exits just above where the steam enters.

The part could be the same as a 'rectification module' as used in LM heads -

https://www.aliexpress.com/item/1005005759819813.html

Just keep an eye on the water level and shut it down and top-up the water whenever it runs low during those marathon stripping sessions!

[Bolverk]

Thanks,

Yeah that's the same type of feed Alex used in his here


Shown here


Honestly I planned to go this route for a long time.

This up side is that you don't need to fabricate a stand or mount the down side is heating up a larger volume of water in the keg. On my keg with the element mounted as low as possible still needs a minimum of 3 gals to operate safely. The tube boiler is like .25 gals and will come up to temp much faster. In the end its all a trade off of what you want to do.